The Large Telescope Virgin
It happened up on Pine Mountain at the University of Oregon observatory. It was a cold, cloudy day and I was there to begin my training as a Tour Guide/Telescope Operator for the 2007 summer season. A few others where there, and only one who had less experience than I with astronomy. I don’t so much consider myself an amateur astronomer as a beginner, with only a year under my belt. My personal ‘scope is a Celestron (read: Made In China) 114EQ. This means it’s 114 millimeters or 4.5 inches in diameter. It’s not what some would call a “true” Newtonian reflector, as it has another mirror/lens at the base of the focuser, but the word catadioptic is too hard to say.
When I first held the controls for the 24 inch telescope (two foot diameter primary mirror), a chill ran down my spine. Hovering over us was at least a ton of scientific instrument. It had to be as big and heavy as the Nissan Pathfinder I rode in up to the mountain. Two obstacles were immediately apparent: the electrical cord that ran from the wall up to the roof of the dome for the dome shutter, and the large rolling ladder steps used to reach parts of the scope. Our instructor watched me like a hawk as I tried to remember all I could about right ascension and declination and fumbled with the industrial gantry style control paddle.
Firing up this monster (laugh: compared to more well known observatory ‘scopes, this one is a baby) is an auspicious event. No less than three switches must be activated, in correct order, just to get power to it. There are computers to wake up and dust covers and tarps to remove. The machine is one part fragile and one part heavy equipment, and all terrifying for the neophyte. The dome must be rotated and the shutter opened, and there are quirks to every moving part involved. If you move the scope too far, it’ll break internally. Too far down, the mirror could fall out. If the shutter is opened too wide, it may fall off the back of the dome. This is an old observatory, and was built in what is still fairly rugged country. I can only imagine the challenges of building, maintaining and operating the larger observatories at the top of larger mountains such as Mauna Kea.
The control paddle moves the ‘scope East, West, North and South in two different speeds, and neither is labeled “fast” and “slow”. No, they’re labeled Slew and Set, respectively. The controls for rotating the dome are on the paddle, but the shutter control is on the wall. The shutter is split so you can raise one part higher than the other, or raise them together, depending on how low or high , relative to the horizon, you want to view. The latch mechanism for the two halves is up on the dome, and you need the large rolling steps to get to it.
Moving the steps around is a chore. You have to watch that you don’t get snagged on the shutter’s power cord or hit the focuser of either the main telescope or the finder ‘scope. The steps need to be moved around approximately two thirds of the floor during a night’s operations. The very act of locking it down can cause it to move in a manner that can slam the top into the delicate instruments.
Slewing the scope is a butt-puckering event to be sure. It’s large and heavy, and once it gets going, it does not want to stop. They call it “coasting”, and that it does. The longer your finger is on the direction button, the faster it goes and the longer it coasts. Often one of the old relays in the large blue electrical boxes on the wall gets stuck, making a bone jarring buzz, and you have to bump the button you were using to free it. If you bump another button, you run the risk of shocking the gear train and breaking something. Parts are nearly impossible to get for the telescope, and installing them is no easy feat. There are large, clock-like vernier dials set into the base of the scope, and if making sure the scope isn’t destroying something in its travels isn’t enough to boil your brain, watching these will finish the job. One is right ascension and the other is declination, and they’re not intuitive at all. It takes some staring and concentration to see if you are, in fact, where you want the ‘scope to be. It is a minor athletic event to keep an eye on the scope, the steps, the shutter power cord, and these two dials.
But it is definitely worth it. The first time you find and are able to see a deep sky object in the eyepiece, you know it was all worth it.